The interior surfaces of tanks for corrosive liquids are lined with a chemically resistant material such as polyvinyl chloride (PVC), rubber, a thermoplastic polytetrafluoroethylene (PTFE), and the like, to protect the inside wall of the tank. Frequently, when the pressure is reduced inside such a lined tank, the lining tends to separate from the interior wall of the tank and will render the tank unfit for further use.
In the prior art these problems were sought to be avoided by applying the tank line webbing to the interior surface of the tank without any adhesive and then pulling the line against the interior surface through a plurality of suction ports. Thus, the tank liner is tensioned through a balance of the inside and outside vacuums exerted on both sides of the lining.
Problems still remained with the foregoing arrangement. The suction from the exterior is exerted only on the parts of the lining that are nearest to the suction ports. This produces an unsatisfactory effect because parts of the lining that are remote from the suction ports are sucked inwardly. The portions of the lining that are sucked against the interior are also likely to peel off, and the entire lining will collapse into to the tank to an extent to render the tank unserviceable when the outside pressure reduction is interrupted for any reason.